Abstract: [Object of the Invention] An object of the present invention is to develop an air curtain device generating parallel air flow based on the knowledge in that parallel air flow generated at the outlet of a turbulent flow runup zone does not include vortex flows and has strong air current interruption performance.

Abstract: A discharge elbow provided with guide vanes includes an elbow of rectangular cross section and magnification f of 1<f?5, one or more guide vanes disposed in the elbow, wherein the guide vane or the guide vanes are made of a curved plate and a pair of flat plates connected to the curved plate. One of the flat plates is located in front of the curved plate and the other is located to the rear of the curved plate. M-number of sub-channels similar to one another are formed in the elbow based on particular formulas, wherein the inner sidewall of the elbow is deformed into a curved plate coaxial with the curved plate of the adjacent guide vane to deform n=1 sub-channel into a coaxial bend channel provided with a uniform breadth equal to the inlet breadth b1 of the sub-channel.

Abstract: A discharge elbow provided with guide vanes comprises an elbow of rectangular cross section and magnification f of 1<f?5, one or more guide vanes disposed in the elbow, while the guide vane or the guide vanes are made of a curved plate and a pair of flat plates connected to the curved plate. One of the flat plates is located in front of the curved plate and the other is located to the rear of the curved plate. M-number of sub-channels similar to one another are formed in the elbow based on the following formulas, whereafter the inner sidewall of the elbow is deformed into a curved plate coaxial with the curved plate of the adjacent guide vane to deform n=1 sub-channel into a coaxial bend channel provided with a uniform breadth equal to the inlet breadth b1 of the sub-channel.